题干
— I think _______ can keep us healthy.
— I agree with you.
A：do exercise
B：exercising
C：exercised
答案(点此获取答案解析）
B
— I think _______ can keep us healthy.
— I agree with you.
A：do exercise
B：exercising
C：exercised
中的氯离子浓度与50 mL 1 mol·L-1的AlCl3溶液中氯离子浓度相等的是